Twilight of an Era examines some of the important events in Canada during the Depression years: the Moose River mine disaster; the great drought on the prairies and the subsequent Prairie Rehabilitation Program; the introduction of a transatlantic air service between Canada and Europe. The film also looks at the major world events that impacted on Canada: the abdication of the king of England; civil war in Spain; Hitler's rise to power and the death of ten year old Margaret Hayworth aboard the Athenia; Canada's declaration of war on Germany.